The present invention relates to an optical device, a wavelength division multiplexing transmitter, a wavelength division multiplexing receiver, and a wavelength division multiplexing transmission and receiving system.
In recent years, optical communications employing a wavelength multiplexing communication method have begun to come into widespread use not only as long-distance communications but also as short-distance communications. Examples of such short-distance communications include communications in a data center.
A wavelength division multiplexing transmission and receiving system used in optical communications employing a wavelength multiplexing communication method includes a substrate-type optical waveguide device which functions as a transmitter or a receiver. The substrate-type optical waveguide device, which is known as a planar lightwave circuit (PLC), includes: a substrate having waveguides provided thereon; and a plurality of optical components which are integrated in the vicinity of a surface of the substrate. Such a substrate-type optical waveguide device can be read as an optical device recited in Claims of the present application.
Non-patent Literature 1 discloses a wavelength division multiplex transmitter and a wavelength division multiplex receiver both of which include a plurality of optical components integrated on a single substrate and use different wavelengths of light beams as carrier waves. In many cases, the transmitter includes laser diodes provided on the substrate as individual optical sources for emitting different wavelengths of light beams as carrier waves. With a plurality of laser diodes of different emission wavelengths, the transmitter can output laser different wavelengths of light beams as carrier waves.